This invention relates to footwear in general and in particular to shoes to be used for sporting activities such as running, jogging, walking or playing games. For convenience such shoes will be hereinafter called "athletic shoes".
The design of athletic shoes has improved dramatically in recent years. Originally such shoes had little or no cushioning in the soles and runners and other sportsmen began to find serious problems in joints and bones as a result of the pounding which occurs during the sporting activity. In recent times various degrees of cushioning have been built into athletic shoes to absorb shocks so as to lessen the negative skeletal impact and improve the perceived comfort to the user. This has helped to reduce the shock forces in the body. However, mere cushioning is not enough. Thus, if of one simply has a shoe which only absorbs all of such forces, this means that a great deal of energy is lost during each stride and so the athlete will tire more quickly.
Therefore it is desirable to design the soles of athletic shoes so that not only are the negative shock forces absorbed, but also the positive energy absorbed must as far as possible be returned to the athlete to enhance his performance and stamina. This is often termed "energy return".
The invention therefore is concerned with this aspect of athletic shoes and it is an object of the invention to provide a high energy return in athletic shoes whilst at the same time providing excellent cushioning.